Abstract: The author of the
proposal, Professor Kleppe, has discovered large trees rooted at a depth
of 120 feet below the existing surface level of Fallen Leaf Lake. Fallen
Leaf
Lake is one of the major watershed areas for Lake Tahoe. Some of these trees
measure over 80 feet tall with a circumference of 15 feet, which is an indication
that they were over two hundred years in age when they died. Carbon dating
has shown that the trees died simultaneously in 1215 A.D. The significance
of this discovery is the fact that for these trees to be rooted 120 feet
below
the surface of the lake, the lake must have been down at least 120 feet for
over two hundred years. This would indicate that a "mega drought"
had occurred. It is critical that these trees be studied and that tree ring
data be gathered to determine whether or not there were wet or relief periods
during these drought periods. It may be possible to learn more about the cyclic
nature of these "mega droughts". If another such drought were to
occur in modern times, it would devastate the affected regions.